1. Field of the Invention
The present invention relates to antialgal compositions, methods of controlling algae, and coating compositions comprising the antialgal compositions.
2. Description of the Prior Art
The presence of algae in various aqueous systems such as latices, paints, coatings, cooling water systems, decorative ponds and the like, can cause deterioration or disfigurement of these systems. For example, painted surfaces may be disfigured by the unsightly buildup of algae, thus detracting from the overall aesthetics of the painted article; cooling towers may lose efficiency due to the buildup of algae on surfaces, thus reducing the heat transfer capabilities of the tower. It is conventional to practice methods which inhibit the algal deterioration of such systems by incorporating a variety of additives or combination of additives that are characterized by having antialgal activity.
A wide variety of materials have been used to control algae in different environments, some of which are: chlorine/bromine compounds, glutaraldehyde, isothiazolones, organotin formulations, copper salts, quaternary ammonium compounds (SD Strauss and PR Puckorius in J. Power, S1, June 1984), and triazines. Each has deficiencies related to toxicity, pH and temperature sensitivity, limited effectiveness, chemical stability, and/or compatibility.
European patent application EP 384661A discloses the use of diphenylethers in antialgal compositions, and U.S. Pat. No. 4,975,111 discloses the use of said diphenylethers with isothiazolones as antialgal compositions.
European patent application EP 143547A teaches the use of oxyfluorfen diphenylether/glyphosate (N-(phosphonomethyl)glycine) mixtures as having enhanced herbicidal activity towards weeds and grasses.
Oxyfluorfen in combination with diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) has been found to be an effective herbicide for weed control in sugarcane fields (HJ Yeh, Taiwan Sugar, 27(4), 125-129, 1980), nectarine crops (MJ Hartley, Proc. N.Z. Weed Pest Control Conf., 40th, 140-143, 1987), and biomass production (P Felker and CE Russell, J. Hortic. Sci., 63(1), 149-155, 1988).
Based on the aforementioned performance deficiencies of conventional antialgal compounds there is a need for more effective antialgal agents that can be used at lower dosage rates, thus being more cost effective for the end user, reducing the pollution load on the affected environmental systems, and reducing the side effects to nearby non-target organisms, such as fish, useful crops, etc.